Catch Cans – Why are they needed

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

Good little video explaining that all engines breathe, also interesting idea locating it in the boot in a race car application.

[NickParticipant Adelaide, SASeries 1 VX Commodore Wagon View build HERE Member since: April 23, 2015 Posts: 75]

Great video, HPA are so informative with their videos.

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

Nick wrote:

Great video, HPA are so informative with their videos.

Agree, I watch a lot of their stuff, very low on the BS factor.

[ImmortalityParticipant 97 HSV Senator 185i 02 VX L67 Calais View build HERE Member since: August 31, 2015 Posts: 535]

It’s almost like they are trying to do a 2 in 1 making a catch can and puke can in one even though in reality they do different jobs.

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

Lol, never heard the term “puke can”.  Is that just in case the engine lunches itself?

[ImmortalityParticipant 97 HSV Senator 185i 02 VX L67 Calais View build HERE Member since: August 31, 2015 Posts: 535]

Fairly much.  If you look at top fuel dragsters They have 1″ hoses coming out of the rocker covers running to big tanks and are there to catch any shit that comes out.

https://www.youtube.com/watch?v=XCIkcNGhgrs

A catch can, part of a closed breather system is more of an oil/air seperator.

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

Got it, pretty familiar with catch cans and their job, in fact, had to do get up to speed for engineering.  That guy that runs the Brock VB look-alike drag car that is on the front cover of the SC mag I was featured runs a catch can with a closed cap when he is on the street, presumably he claims at light throttle loads the total rebreathing back into the inlet works, but when he gets to the strip he swaps the cap over to a fully vented style. Pretty sure what he says he does and what he does are two different things

I would have thought most of the time if an engine lunches itself there are holes punched in blocks, sumps whatever, so no tanks going to catch that?

[ImmortalityParticipant 97 HSV Senator 185i 02 VX L67 Calais View build HERE Member since: August 31, 2015 Posts: 535]

LOL, yep, when you window the block the puke can is redundant but for that they run engine nappies.  If you watch drag racing though they will burn a piston or something similar without actually destroying the engine.  They simply change the cylinder sleeve(s) before fitting 8 new pistons and doing it all over again.  Quiet amazing to watch really.

 

Yeah, for legal reason an enclosed system is a must but most people just vent to atmo….  I think mightymouse catch cans have a valve so they automatically vent to atmo if pressure builds in the can.  For a street driven daily driver type car a sealed system is still best for overall engine/oil health.

[Anonymous View build HERE Member since: January 1, 1970 Posts: 0]

After hosing a couple of litres of Oil out the rear main when mine was in the Tonner I built a variation of a system I ran back in the Supra Days that worked faultlessly.

I run a -10 hose for the Pass side cover to the Catch Can, the catch can has a -6 drain back to the Sump, There’s a -10 Line into the Pipe between the Filter and Throttle Body.

Half way along the -10 line is a 1psi non return valve, on the catch can side of that is a T with a -6 line to a real PCV valve that goes to a port behind the Throttle body.

The Drivers side rocker cover is the clean air in vent and runs to a 2mm restrictor in the pipe between the Filter and Throttle Body.

Under normal use the system works exactly like stock but in high load/blowby situations the non return opens venting the excess into the engine intake, the catch can has a proper baffle system and is full of stainless pot scrubbers for more surface area so it’s quite good at condensing any oil vapor back to liquid, everything else is burnt in the engine.

[cava454Moderator 93 VR BT1 View build HERE Member since: February 20, 2015 Posts: 2 390]

My catch cam has PCV built into it and the filter on top has a one way valve. Same principle as Ian. Under normal conditions works like a regular setup with the addition of the oil separator.

Under WOT It vents to atmosphere

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

All well and good when you have a singe throttle body, ITBs kinda screw that option up…

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